Fire emissions are an important but dauntingly complex source affecting atmospheric composition. The inefficiency of fire combustion leads to a diverse mixture of trace gas and aerosol emissions with a large component of short-lived, chemically reactive constituents. Emissions are affected by a wide variety of factors including fuel conditions (type, structure, quantity, and moisture content), fire intensity, and fire weather (cumulative temperature, relative humidity, wind speed and precipitation). Individual fires also pass through various stages and combinations of flaming and smoldering combustion leading to time varying emissions. These variables also influence plume rise and the subsequent transport and chemical evolution of fire emissions. The predictability of fire emissions is further complicated by their causes. Fires can be initiated naturally (lightning) or by human intervention (e.g., land clearing and agriculture). While fire activity can be predicted on a broad seasonal scale, climatologies are inadequate to provide the information needed to represent fire impacts due to their specific location, timing, and intensity. This is especially true for impacts related to air quality which depend on the intersection of fire emissions and populations and the changes in chemistry that can result when emissions from fires and anthropogenic sources combine. These concerns dictate a strong need for satellite data to inform the understanding of fire processes before, during, and after fire activity.